/Engine/Plugins/Media/MediaIOFramework/Source/MediaIOCore/Public/FileMediaOutput.h
'Enable alpha channel support in post-processing' must be set to 'Allow through tonemapper' to enabled the Key.
[UCLASS](Programming/UnrealArchitecture/Reference/Classes#classdeclaration)(BlueprintType) class UFileMediaOutput : public [UMediaOutput](API\Plugins\MediaIOCore\UMediaOutput)
FString
BaseFileName
The base file name of the images. The frame number will be append to the base file name.
bool
bInvertAlpha
Invert the alpha for formats that support alpha.
bool
bOverrideDesiredSize
Use the default back buffer size or specify a specific size to capture.
bool
bOverridePixelFormat
Use the default back buffer pixel format or specify a specific the pixel format to capture.
EFileMediaOutpu...
DesiredPixelFormat
Use the default back buffer pixel format or specify a specific the pixel format to capture.
FIntPoint
DesiredSize
Use the default back buffer size or specify a specific size to capture.
FDirectoryPath
FilePath
The file path for the images.
FImageWriteOpti...
WriteOptions
Options on how to save the images.